无速度反馈的航天器姿轨耦合跟踪控制

An attitude and position coupled tracking control algorithm for spacecraft without velocity feedback is proposed in this paper. A coupling dynamics model for the spacecraft with perturbations and parameter uncertainties based on dual quaternions is established firstly. Then, based on the theory of immersion and invariance, a velocity observer is designed. The observer estimates the angular velocity and the linear velocity together, and suppresses the nonlinear terms by dynamic scaling injection. The convergence of the observer states and the boundedness of injection gain are analyzed theoretically by Lyapunov function, and the exponential stability of the observer is proved. The rate of convergence of the observer states can be changed by adjusting the gains. Finally, a PD position and attitude tracking controller is designed. The controller can realize tracking of any attitude and position of the spacecraft. The asymptotic stability of the closed-loop system of this observer-controller cascade structure is analyzed. Simulation verifies the effectiveness of the observer-controller system and its robustness to uncertain parameters and measurement noises.